Evidence of a Hepadna Virus Infection in Manchurian Chipmunks

Abstract

In attempting to find a new host of hepadna virus, sera of Manchurian chipmunks (Tamias sibiricus asiaticus ) were tested for serologic markers of hepatitis B virus and virus like particles. Of 47 tested animals, HBsAg reactivities were found in sera of 6 animals and anti-HBs in 7 animals by radioimmunoassay. The HBsAg-positive sera were examined by electron microscopy. Numerous spherical particles 21 nm in diameter and many spherical double-shelled particles 41 nm in diameter, which look similar to Dane particles, were observed in all the HBsAg-positive sera. The amount of 41 nm particles seems to correlate with the titer of HBsAg reactivities. Histologic examination of liver tissues from the HBsAg and particles-positive animals showed no evidence of liver disease. The detection of HBsAg reactivities and particles similar in appearance to the particles of hepatitis B virus in sera of Manchurian chipmunks strongly suggests infection of a hepadna virus in these animals.